The Importance of Histhopathological and Immunohistochemical Studies of Anterior Capsule Basement Membrane in Diabetic and Non-Diabetic Patients

Abstract

Abstract: : Purpose: Our previous report has shown that diabetes increases the thickness of the anterior capsule basement membrane (ACBM), which correlates with age of the patient and duration of the disease. The purpose of this study is to determine whether the increasing thickness of ACBM is related to the expression of collagen III and/or collagen IV. Methods: In this prospective randomized study, anterior lens capsule specimens were collected from routine phaco-emulsification cataract surgeries with capsulorexis, performed by two surgeons using the same equipments and techniques. Fourty (40) lens capsule specimens of diabetic patients (DP) and 40 of non-diabetic patients (NDP) were formalin-fixed and paraffin-embedded. Twenty specimens of DP and 20 specimens of NDP were tested for collagen III expression and the remaining specimens were tested for collagen IV expression using the immunoperoxidase method. Results: Collagen III was not expressed in the ACBM of all DP and NDP specimens . Expression of collagen III was detected in the cytoplasm of underlying epithelial cells of both DP and NDP specimens. On the other hand , collagen IV was positive throughout ACBM of all DP and NDP specimens and was negative in the cytoplasm of underlying epithelial cells. Conclusions: Collagen IV was found to be a major component of the anterior capsule basement membrane of both diabetic and non diabetic patients . Collagen IV may play an important role in increased thickness of anterior capsule basement membrane in diabetic patients. Further studies should be performed in order to evaluate whether over expression of collagen IV is the main reason for early formation of senescent cataract in diabetic patient.

Keywords: diabetes • cataract